Orcas Diverging?

Evolution in Action

The idea of species as fixed groupings of individual living beings is a slippery one, and species are not easily defined nor delineated.  This is one reason the creationists claim that they accept micro- but not macro-evolution in defense of their holding on to their belief in separate creations for all kinds, or baraminology.  Wilkins, the Modern, explains briefly how the concept of species itself evolves:

Some years ago, I published an idea that I think might be the resolution to this (2003) in which I argued that species is like any other property of organisms, something that has evolved in its own way. The reason there is no universal notion of species for the same reason there is no universal notion of leg: species, like legs, are the outcome of evolution. In other words, these kinds themselves evolve. This applies also to other apparently universal aspects of biology: genes, or rather replicators, cells, individuals, and so on. It is not the case that, as Dupré thinks, that anything goes, but that there are evolved modalities, as I called them – ways of being whatever it is that we are trying to understand. This applies not only to the organisms and their traits, but to the kinds of organisms, and even to the kinds of kinds. Taxa, units, ranks, entities, systems – all these are evolved, and so to understand what it means to be, say, a bird species or a eukaryote gene, you need to understand the evolutionary relations of that group.